


Creep

by high_and_down



Category: Sherlock (TV), The Exorcist (1973)
Genre: Alternate Universe - Supernatural Elements, Bugs & Insects, Freezing cold, Hiccups, Latin, M/M, a bit spooky, sherlock is being stalked, things that go bump in the night - Freeform, william peter blatty
Language: English
Status: In-Progress
Published: 2014-08-27
Updated: 2014-09-25
Packaged: 2018-02-15 00:15:15
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 2
Words: 4,613
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2208396
Author URL: https://archiveofourown.org/users/high_and_down/pseuds/high_and_down
Summary: <blockquote class="userstuff">
              <p>Following a series of bizarre and eerie incidents at 221B, Sherlock becomes increasingly unstable both physically and psychologically.<br/>While struggling to explain this in a rational sense, John puzzles over an odd cluster of murders that may or may not be the work of a serial killer, and begins to question the certitude of science as well as his faith in himself.</p><p>Heavily influenced by William Peter Blatty’s ‘The Exorcist’.</p>
            </blockquote>





	1. Chapter 1

It happened when John was out. Out at the shops, out on a date, out for long enough. Sherlock knew he would have plenty of time to indulge and have his damning evidence brushed away before John’s return. He had lived with John for long enough now (John had moved in four months ago) to know that his occasional use of cocaine – and more, though he had never revealed as much to John – was not at all approved of. He held up the clear solution to the light and flicked it. 

In the back of his head there began a silky whispering, something almost physical, like a gauze ribbon being brushed against his skull. It flickered and dimmed, retreating into shadow, and the more Sherlock pursued it, the more it shifted and slipped about, like a leaf on water’s surface. It bothered him. Was a headache coming on? He could feel a sort of buzzing in his cranium, like a radio station that needed to be properly tuned. 

The room grew cold. Sherlock lowered the cocaine warily, feeling that something had happened. He didn‘t know what, couldn’t put his finger on it. The murmuring in his head grew from a soft whisper to a hoarse mumbling, and Sherlock was alarmed to find that he could make out slivers of syllables in Latin. Was he finally, actually losing his mind? Was this it? He wished suddenly that John would return home early. He felt nauseous, and his extremities began to grow numb.

The temperature in the room plummeted and the fire in the hearth blinked out. 

The only light in the room was a faint orange glow through the windows from streetlamps. His eyes naturally searching out the only source of light, Sherlock gazed at the silhouettes of trees and signposts that were cast along the floor in the shadow of the window. His skin prickled. Were they moving, or was he just extremely dizzy?

The intermittent Latin mumbling that Sherlock knew was not his own voice, but a dark, scratching voice inside his brain, became louder and interspersed with a terrible static screeching. In his mind’s eye, a face flashed once, twice, colourless and white, cloaked in shadow, bright red lips laughing and jeering. 

Sherlock was terrified. For a split second, he thought that the walls of the flat were writhing with mangled pieces of human bodies, but upon blinking, the flat was revealed to be totally dark. 

There was a slam at the front door downstairs, and Sherlock breathed a sigh of relief. John? But that wasn’t right, no, the footsteps were much heavier and slower than John’s.

The door to the flat swung open silently in Sherlock’s peripheral vision. 

The room became so cold that it hurt to inhale. The glass vial containing cocaine solution splintered and shattered. Frantically, Sherlock searched for whoever had come through the door, but nobody was apparent in the gloomy lighting. He was absolutely certain that there was somebody in here, staring straight at him. He felt it. He could hardly breathe. 

The front door downstairs slammed, and abruptly the unbearable presence that had been filling the flat vanished, the fire flickered back to hearty life and the agitated Latin muttering in his head disappeared. 

John thundered up the stairs and entered the room, eyes going straight to Sherlock who was sitting in shock, broken cocaine vial at his feet.  
“Sherlock!” John cried. He rushed over and checked the little box that contained the tourniquet and needle to see if Sherlock had managed to take any of it. He sighed in relief when he saw that the syringe was still locked in its little nest. He took Sherlock’s hand in his, but almost dropped it in alarm when he felt how cold Sherlock was. He was freezing. 

“Jesus, Sherlock, why are you so cold?” John was at a loss. Sherlock was unnaturally cold, given the fire was plenty warm. He could see slow chest movements indicating breathing, but otherwise Sherlock was totally unresponsive. However, John was fairly used to that. Mind Palace and all that. But Sherlock was so cold he had to be borderline hypothermic. It didn’t make any sense. 

“Let’s get you a blanket.” John quickly collected Sherlock’s treasure box containing the cocaine paraphernalia, cleaned up the shattered glass vial and piled blankets of top of him. 

Sherlock was, for the only time thus far in his life, lost and afraid. Truly afraid. He was teetering between madness, or … something else, something which might be decidedly worse than madness. Something that he could not fathom at all, and not knowing was bad enough for Sherlock, but the feeling that knowing could eventually be even worse sent him reeling. He could not pretend the whole thing was imagined, or a dream. 

There was an oily feeling in his head, like a residue that he couldn’t shake off. 

Like something had left its trails there.


	2. Chapter 2

**Summary for the Chapter:**

> The first stage is infestation.

Sherlock had not slept. He’d spent the whole night in the living room with the television switched on, volume on low, fluffing around with his violin and some experiments. Nothing could hold his attention. He obsessed over the voice – voices? – that had invaded his mind, and the face that he had seen inside his head. The dilemma was that he didn’t want to think too much about either, because he was still frightened, and being frightened of something in his head was in itself a horror for Sherlock. He didn’t dare research Latin terms right now. He feared the outcome. It was akin to sensing a shadow behind you, but not turning to face that shadow for fear of what it could be.

Morning came softly, slowly, little wisps of pale light curling through the flat. Sherlock switched off the television and made himself busy with experiments. He didn’t want John to think anything at all was out of the ordinary. Bad enough that he had come home to Sherlock’s comatose and hypothermic state last night.

As the sun started to show John appeared at the door to the kitchen, looking extremely tired. “Morning,” he mumbled, not looked at Sherlock but turning to make himself tea. “’Spose you’ve been there all night.”

“In somno expectat abyssus,” Sherlock replied without thinking.

John’s head popped around the door. “What?”

Sherlock frowned slightly. “What?”

John stared at him, brow creased. “What did you say?”

“I didn’t say anything.”

John stared at him for a second longer, then returned to the kitchen muttering to himself about, “Mental,” and “Expected nothing less,” and various other complaints that Sherlock ignored as he wildly tried to remember if he had said anything just then. Surely it was normal enough for his behaviour to puzzle and probably irritate John, but he did have a nagging feeling that something important had happened. Should he put it down to not enough sleep? No, that had never been an issue before. Sleep was easily forgone, sleep was wasteful, let the brain idle, sleep was an abyss –

Sherlock stood abruptly and began to put on his overcoat. He was still wearing his pyjamas but he hardly noticed. John gave him another funny look, tea in one hand and dog-eared novel in another. _Second-hand book, John finds it boring but is forcing himself to read onwards in the belief that it will gain him intellectual points and a deeper understanding of –_ Sherlock shook his head. Hand on the doorknob, he hardly knew what he was doing, but he needed to get out, get some air, clear his head.

“You realise you’ve forgotten your shoes?” John sounded amused, but there was a faint underlying tone of worry there. “Bit nippy for a six am barefoot stroll.”

Sherlock ignored him (again, forever, every time) and whirled out the door.

\---

John didn’t see Sherlock all day. He waited around an hour or so before giving it up as ‘the erratic and bizarre flatmate strikes again’ and went to work. Like any other day, he did spend a good portion of that day worrying about Sherlock and what he was up to.

“Wandering around barefoot at the crack of bloody dawn,” he mumbled as he signed endless paperwork. “Catch his death, bet he comes crying to me.” It wouldn’t be the first time that Sherlock’s conduct baffled and worried him.

When he returned home, it was already getting dark. “Sherlock!” he called as he switched on the lights in the flat. It was terribly dim and the fire was not lit. Explains why it’s so cold, he thought, trying not to shiver.

Sherlock was lying on the sofa in much the same way as he had been the previous night when John went to bed, wrapped in his dressing gown, his typical damsel-in-distress pose taking up both armrests and all the seats.

“Alright there?” John thought he’d better check that Sherlock was still alive, at least. “How was your morning stroll?”

He was used to not getting any response. It would have thrown him to actually get some response.

The flat was so chilly. He rubbed his arms, quickly set about lighting up the hearth and gave a little sigh of satisfaction when it was done. Small orange flames flickered to life, emitting little heat for now but all the same adding some life to the gloom that was setting in with dusk.

“Is there a construction site nearby?”

John turned, surprised at the non sequitur and also at Sherlock’s willingness to display this lack of knowledge. When did Sherlock ever not know what was happening?

“Er, not that I know of. Why do you ask?”

Sherlock shook his head mutely and fell back into his disillusioned flop over the sofa.

The flat felt hollow, somehow. Maybe it was the cold, the silence, the funny mood that Sherlock seemed to be in – funny in what way, John could not explain, but it was not a typical sulk at all; he switched the television on to try to encourage a slightly more lively atmosphere. A well-known newsreader was describing a victim, a community favourite who ran marathons for charity, volunteered at homeless shelters and campaigned for a cleaner environment. She had been found this morning (John guessed he had missed the bulk of the report as they were coming now to a close with the information) killed by some monstrous means that the newsreader did not describe. He caught a snippet of the suburb where the crime scene was located, Clareton, at what must have been the end of the article, before the programme moved onwards to detail the escalating civilian death toll in religiously motivated warfare between Israel and Palestine.

Clareton could be said to be just about in their backyard. Perhaps this could be an excellent motivation to propel Sherlock out of the funny reverie he seemed to be stuck in. He glanced at Sherlock to see if he had leapt up in glee, as was expected. Sherlock was sitting up, looking somewhat interested, but he didn’t seem as excited as he should be. John wondered if he was coming down with something. It would certainly explain the subdued behaviour. He tilted his head at Sherlock.

“Well? What do you think, then?”

Sherlock shrugged, which in itself was odd, because surely he should be much more animated by now at the prospect of a gruesome murder so close to home. “Can’t know until I have more data. Lestrade hasn’t called.”

As if on cue, John’s mobile rang. It was Lestrade.

“John, sorry to bother you, terrible timing I know, Sherlock’s phone seems to be disconnected. Has he lost it or something?”

John stared at Sherlock, puzzled. He could see Sherlock’s mobile on the kitchen table. Was it working? He’d have to check later.

“Need you to look this over, if you can. Do you have time? Terrible thing, terrible. It’s just right by your flat.”

“Ah …” John took in Sherlock’s blank, uninterested expression. “Yeah, be right over. Can you text us the address?”

It wasn’t far at all, close enough to walk probably but they didn’t have the time. There was a small huddle of news reporters and their crews, pedestrians walking by and people in general gaping and gawking. They had to push through the crowd to get to Sally Donovan who greeted Sherlock with her usual, “Freak,” but Sherlock only gave her a passing glance. This surprised Sally, who looked confused and raised an eyebrow at John, who only shook his head.

The murder was awful. The victim, mid to late forties, female, previously of good health, had been destroyed. Her body was covered in scrapes and gashes everywhere. Blood speckled her torn clothing and ran in little rivulets down to the ground. Worst was her neck, which had been stretched, stretched and stretched, until the skin was twisted and warped and dark underneath the surface from the blood being split and spilled away from its proper veins. Like her head had been forcibly pulled away from her body with enormous strength. John was stunned. From a medical point of view, he had never seen anything like it, nor could he possibly imagine it.

They found Lestrade discussing with the chief medical examiner who looked just as worried and puzzled as John felt.

“… hardly humanly possible,” John heard before they both looked up and saw John and Sherlock standing there.

“John! Sherlock! Thank god. I am completely in the dark here. It’s terrible, so terrible.”

John turned to ask Sherlock what he thought, but Sherlock was hanging about by the body, standing next to it and looking down at the face, which was twisted beyond recognition. The prominent features had all been heavily bruised, the skin pulled and corrupted and crumpled. The medical man in John was at a loss to find a logical explanation, subconsciously categorising the vast amount of damage to scalene and trapezoid muscles, strong muscles, muscles that would hold on at all costs. Sherlock was just staring, breathing heavily, looking a little off-colour. John wondered why his sharp, analytic gaze wasn’t flitting all over the corpse. He sidled up and whispered, “Hey. Everything okay?”

Sherlock gulped, hiccupped. “Single, no significant relationship, well-known amongst locals, constantly volunteering at public events and donating as much time as she possible can to charitable causes. She doesn’t have any enemies because of course who could possible begrudge someone as saintly as her, no motive as she hasn’t been mugged or sexually violated, all her valuable belongings are still on her –“ and here he stopped and hiccupped again, and seemed to sag a little. He even leaned on John’s arm for a moment.

If John hadn’t been worried before he certainly was now. Sherlock was definitely coming down with something. He found Lestrade and explained the situation, finishing with a firm, “I need to get him home to rest.”

He knew that Lestrade relied on their help and that this was a case that seemed to need, more than ever, to be wrapped up as quickly as practicable. But his concern for Sherlock, added to his disinterest in the crime scene, dictated that this be put on hold for at least a short while. He hoped that Lestrade would understand. Even Sherlock Holmes was only human.

Lestrade nodded. “Fine, but I’ll need as much help as I can get with this one.” His gaze on John became earnest, begging. “It’s a terrible one, John. I just don’t know what to think. How could somebody stand to disfigure a fellow human so badly? Why? The amount of spiteful willpower … ” He trailed off. He muttered again, mostly to himself, “I just don’t know what to think.”

\---

John made Sherlock get into bed as soon as they were home. The loud, shaking hiccups had not subsided but that was the least of John’s problems right now. Sherlock’s room was even colder than the flat now. He wondered why the flat was so cold while they were only in spring. Sherlock fell into a fitful, tossing doze as soon as John made him lie down and put the blankets over him.

His gaze became soft. Sherlock sleeping was something wondrous and innocent. It relaxed his usually drawn, snappish features and made him impossibly human. John traced a hand over the curve of a shoulder and patted Sherlock gently, as if to reassure him.

It was well past midnight and John found himself yawning. What a day. A day in the life of John Watson, flatmate and blogger to one incandescent Sherlock Holmes.

He put on his warmest sleeping clothes and crawled into his bed. He briefly thought about the crime scene that was so bizarre and awful, but very quickly tumbled into dreams.

The morning came much sooner than he would have liked, for he felt that he had not had enough sleep by miles, but once the alarm went off that was it. He had to get up. After his morning toilette was done, he went to check up on Sherlock. Sherlock was sitting bolt upright at the edge of his bed and staring intently at the walls.

“Are you feeling better?” John queried, wondering if Sherlock had indeed slept at all.

“There’s construction going on downstairs,” Sherlock replied.

“Why – what are you talking about?”

But John’s curiosity was interrupted by a dull tapping noise that sounded like metal plates being hammered into place. It did seem to be coming from downstairs, so he quickly ran down to check, and asked Mrs Hudson if there was work being done there or nearby. There wasn’t.

When he returned to Sherlock’s room the noise had stopped. “When did that noise start?”

Sherlock’s answer was dreamy. “Oh, I don’t know. About an hour or two ago.”

John frowned. He hoped like hell it wasn’t some little rodent running around inside the walls. “Do you want some breakfast?”

He was pleasantly surprised when Sherlock nodded. “Alright, then, I’ll go and fry up some eggs.”

Entering the kitchen gave him a bit of a shock (although by now nothing should have shocked John, really) because Mycroft was standing in the door, silent and imposing.

“God! Good – Good morning.” John eyed him. Mycroft always looked so serious. For that reason, it was quite frightening when Mycroft took the pain to smile at him, as he did at that very moment.

“Can I offer you some breakfast? Eggs?”

“No, I’m afraid my physician has imposed strict limitations upon me for the sake of my cholesterol,” Mycroft said. He sat himself down gingerly in John’s armchair. “I would welcome a cup of tea.”

At that moment Sherlock trundled into the room. Mycroft looked at him. John looked at him looking at Sherlock. Mycroft appeared, heaven forbid, perplexed. “Are you not well, Sherlock?” he enquired gently.

“I’m hungry, that’s all,” Sherlock muttered and brushed into the kitchen to observe John preparing tea and eggs. John and Mycroft shared a moment of silence, each praising the moment that Sherlock admitted to wanting food, and at the same time wondering.

Mycroft seemed distinctly uncomfortable. Why that was could be anyone’s guess, but he kept his eyes sharply trained on Sherlock, who as usual ignored him and did not speak to him at all.

Oddly enough, Mycroft excused himself much sooner than John had expected (or could have hoped for) with a last unreadable look at Sherlock.

John suddenly remembered that Sherlock’s mobile was not working, according to Lestrade. He searched for it while waiting for the eggs to finish up, checked it was on and fully charged, and tried to call it with his own mobile. It wouldn’t connect. His mobile showed the ‘Calling…’ screen but Sherlock’s phone didn’t seem to be receiving anything. John frowned. He could hear the dial tone ringing on his phone, suggesting it was connected. “Bloody technology,” he groaned. He decided to leave it for now and try to get it sorted out at the shops on Monday.

The smell of bacon and fried eggs filled the flat and John quickly set down two plates. Sherlock was sitting at the kitchen table, fingers tapping restlessly on the edge of a glass beaker. He looked at the plate that John put before him but made no move to eat it. John didn’t push him as he knew Sherlock was extremely volatile when it came to food. If he could get Sherlock to eat any of it at all, that would be an achievement.

“Do you feel well enough to visit Lestrade?”

“I’m fine,” Sherlock said sharply.

“Good to hear.” John felt that Sherlock was getting more and more prickly. While it was true that he was often snappish and dismissive, Sherlock had been strangely ill-tempered, cruel even, and vague. He hadn’t rattled off any of his spitfire deductions in the last few days at all. And he was looking very tired. Surely all he needed was a good corpse to engage him again.

They headed to the morgue to visit Molly, who now had the body from the crime scene yesterday. She too noticed Sherlock was not quite well. She kept the small talk to a minimum for once and told them what she had managed to glean so far.

“It’s pretty overwhelming. I mean, the amount of force that would be necessary to create such a hyper-extension of the neck is … well, it’s just not possible. But someone has to have done it to her. There’s no way it was an accident.”

John was quiet for a moment. He’d seen a lot of things during his service, and he knew that humans were capable of many things. Things which could be considered impossible, outside the reach of human effort. Great things and appalling things. But the brute force and the motivation, too, required for such an act, was unimaginable. No human could be this strong.

“It’s like he tried to pull her head right off…”

Sherlock looked up from his perusal of the body. “He?”

“Well, it would have to be a man, wouldn’t it?”

“As you have just stated, the force necessary for such an action is not attainable by any human whether male or female. Therefore concluding that the person who has done this is outside of the typical definitions of human capability necessitates that this person may also transcend gender stereotypes.”

John felt a little trickle of relief. There was the Sherlock he knew and loved. He smiled a bit – inappropriate, a bit, smiling in a morgue – and felt a weight lift from his shoulders as Sherlock continued on his litany.

\---

When they got back to the flat John left almost immediately to go to the shops. He wanted to get a couple of things in case Sherlock was in fact sick with a flu or virus, and they were running low on groceries. He left Sherlock sitting at the table, tinkering at one of his experiments. Back to normal! With a bit of luck, Sherlock was finished with that strange and distant moodiness that had clung to him for the last few days.

With this thought in his mind, there was a spring in John’s step as he returned from the shops, milk and bread and fruit in plastic bags as well as a couple of over-the-counter flu pills and some hopeful packet soups to try to fatten up his flatmate. All he’d needed was a corpse. Typical. He smiled to himself as he climbed the stairs, unable to help himself.

Sherlock was nowhere to be seen when John entered the kitchen, but as he passed Sherlock’s door to put away some more shopping, he realised Sherlock was in his bedroom. He heard a faint muttering that was undoubtedly Sherlock’s baritone; it sounded as if he was having a serious conversation. He couldn’t make out any words, but the hairs on the back of his neck rose as he heard what seemed to be another voice answering Sherlock. Was somebody in there with Sherlock? The voice was hoarse, deep too but not quite as deep as Sherlock’s voice. Feeling like a burglar, like somebody who was somewhere they were definitely not supposed to be, he crept closer and tried to focus on the conversation. A quiet little voice in his mind said _, and what of it, if Sherlock does have somebody there with him? What right does that give you to eavesdrop on private talk?_

The foreign voice rose slightly in volume. John thought it sounded vaguely accusatory, but it seemed to be in a language he didn’t understand. There was something very hostile about it.

Without warning, Sherlock’s bedroom door banged open. Sherlock almost tripped over John in his hasty exit, looking at John with great surprise. His face was almost grey, two bright spots of colour on his cheeks, his eyes red-rimmed and that opalescent blue shining like bright neon in its fervour. Sherlock seemed to be aware of John’s eyes darting all over him, for he barged forwards and snapped, “Move!”

John didn’t budge. He looked around Sherlock’s looming frame but didn’t see anybody apparent within the room, nor anywhere. He almost didn’t want to ask. “Who were you talking to?”

Sherlock’s mouth thinned and his jaw clenched. “None of your business. Now get out of my way.”

Brushing aside Sherlock’s uncharacteristic belligerence, John persisted. This felt wrong, like he was putting his feet in something sticky that would follow his footsteps forever after. “You weren’t speaking in English. What were you doing?”

Losing his patience, Sherlock tossed his head. “Ruminating, canvassing a theory.” And with that, he _pushed_ John, shoving past him to get out of the bedroom. In the brief moment that their bodies pressed together, John felt simultaneously how very thin Sherlock was – more than ever, to the point that he felt like a bundle of sticks – and how cold Sherlock was, even through his unwashed, crumpled dress shirt.

Like a thunderclap, all of a sudden, there was a loud, sharp _BANG_!

John instantly dropped to the floor (a second nature since the military service) and looked wildly around. Nothing was out of place.

Almost instantly, there followed an ominous knocking in the walls of Sherlock’s bedroom that echoed down the hallways, ringing in John’s ears. It grew louder and louder, always the same rhythm – boom, boom, boom. The same knocking that Sherlock had thought was a construction site.

It took every fibre he had to push down the mounting panic and distress that was washing up over him, sharp and sickly. To disguise his stress to himself and anybody who might be looking, John cried out, “Those damn mice!”

Just as suddenly, the knocking stopped.

John was shaking. Oddly he had the sensation of standing on the edge of a cliff or an abyss. As if he was teetering; and he nearly put his arms out to wheel around for balance.

A cold draft brushed past the back of his head and neck. He shuddered, and pushed away the hard little thought that rose in his mind, that told him that all was not right. Was there a window open somewhere in the flat? Letting in cold air like that, no wonder Sherlock seemed unwell. Feeling like an intruder, he cast a quick look around the inside of Sherlock’s bedroom. It looked fine, apart from a couple of dead cockroaches on the floor in the corner that needed to be swept up. The window there was shut, no doubt about that. Sherlock could be heard out in the kitchen slamming pots and cups around, which was normal enough ... nonetheless, John’s heart shrank a bit, realising that things were not back to normal at all.

\---


End file.
